Short Answer: The latest Java Runtime Engine (JRE) lets you use all of the features of this website.

Long Answer: Much of the site relies on Java applets, and you need a Java Virtual Machine (JVM or VM) to run the applets. The JVM is included in the Java Runtime Engine, which also lets you run standalone Java programs.

There are two issues involved. The first is whether or not you have a JVM. The second is having an up-to-date JVM. Old browsers (and some new ones, e.g. MS Internet Explorer 6.0) do not come prepackaged with a JVM. Other browsers (including IE 5.0) do have a JVM; however, it may be old or otherwise incompatible with some newer applets. Installing the latest JRE solves many compatibility issues with the site.

•I have the latest version of Internet Explorer, but nothing works! Help!

A new installation of Microsoft's Internet Explorer 6.0 will not have a Java Virtual Machine. You need to download and install the Java Runtime Engine (see above).

•I installed the latest Java Runtime Engine (JRE), but some applets are still broken!

Check the settings of the Java Plug-in. Go to Control Panels and open up the Java Plug-in. Select the Browser tab, and make sure that the JRE is the default for your browser.

•Some of the buttons in the page seem to have disappeared. How do I get them back?

Click a little above the area the buttons should be, and drag downward so as to highlight the invisible buttons. Now the buttons should magically repaint. Another way that works is to do a "Reload Frame." (Blame Netscape and Microsoft for this bug.)

•How do I print the graphs outputted by the simulators?

The short answer is "you can't" unless you have a screen capture program.
The long answer is: due to a security restriction on unsigned Java applets,
the plots cannot be printed, unless they are part of a HTML file. If you want
to print out the graph plotted on a applet embedded in a HTML file, you can go
to the file menu and select Print. If this is unacceptable, let us know.

That's a bug in our interface! (We haven't tested on Macs, or UNIX as much).
Try the interface on a MS Windows machine (if you have access to
one), but let us know how you got the error.

•I click [Run xxx] but nothing shows up.

Short Answer: Either Java is not installed and enabled, or there's a bug in our Java applet's code.
Long Answer: Sometimes it takes the simulator up to a minute to process your input, if your simulation domain is large. When the simulator successfully finishes, you will see a "Run OK" status message above the [View plot] button in the lower left corner. Also, the Java plotter may need to download up to 1MB of line or contour data from the server. That can be quite slow over a modem connection. So that maybe that's what's holding it up. In those cases, you just have to be more patient, or grab the files and download and plot them yourself from the [Experiment] => [Files] menu.

•I'm stuck in one of the simulators, how do I get out?

Hurry! Click this! You can also click on the [Exit] button in the top frame.